The present disclosure relates to a control device that controls a vehicle transmission device.
There has been used a vehicle transmission device including a fluid coupling having a lock-up clutch. For example, Japanese Patent Application Publication No. 201247254 (IP 201247254) discloses a vehicle transmission device including a fluid coupling having a lock-up clutch, and a speed change mechanism, on a power transmission path connecting an internal combustion engine and wheels. JP 2012-47254 A discloses, with regard to control of the vehicle transmission device, that slip start control is performed to slip-engage the lock-up clutch when the vehicle is started.
However, JP 201247254 A does not include a specific description about how to control the engagement pressure of the lock-up clutch in the slip start control. Specifically, the speed change mechanism disclosed in IP 201247254 A is capable of performing only continuously variable shifting that continuously changes the speed ratio, and JP 201247254 A does not include any specific description or implication about control of the engagement pressure of the lock-up clutch in the case where the speed change mechanism is capable of performing not only continuously variable shifting but also stepped shifting that changes the speed ratio in a stepwise manner.